Method of mining coal.



11. A. KUHN. METHOD or Mmm@ COAL.

APPLICATION FILED AUG. I4, I9I4.

PatentedJ une 4. 1918.

2 SHEETS-SHEET 2A INVENTOFL. i( a 754%; p/Wd HARRY A. KUHN, 0F PITTSBURGH, PENNSYLVANIA.

' METHOD or minne conn.

To all whom z't may concern.'

Be it known that I, HARRY A. KUHN, a citizen of the United States, and resident of Pittsburgh, in the county of Allegheny and State of Pennsylvania, have invented a new and useful Improvement in Methods of Mining Coal; and I do hereby declare the following to be a full, clear, and exact deseription thereof.

My invention relates to method of mining coal.

The object of my invention is to p rovlde a simple and eilicient method of minl coal in which the coal, instead of being s ot or expanded so as to break it up into small lumps and fine coal, is so shot or expanded as only to release the great mass of coal along its lines of cleavage, so that when a force is applied to under-mine and dislodge a mass of coal, the force so applied will act to break the coal into lumps substantially along its lines of cleavage, so that the coal can be removed in large lumps, thereby creating a great saving and at the same time, increasing the value of the coal, which commands a higher price in the form of large lumps than in small lumps, or slack form.

The invention consists, generally stated, in undercutting the wall of coal, shooting or expanding the coal at a point above the undercut, thereby lowering the mass of coal below the points of expansion into the undercut, and at the same time, fracturingor releasing the mass of coal above along its lines of cleavage, making a kerf in the upper mass of coal at an angle to the line of the undercut, whereby the coal is so weakened and loosened alon its lines of cleavage that the coal may e easily dislodged from below by the vibration or undulating eii'ect of machine such as illustrated and described in application filed by me on the 18th day of May, 1914, Serial No. 839,333.

In the accompanying drawings, Figure 1 represents a cross-section of a mme, showing a mass of coal which has been undercut; Fig. 2 is a like view after the shootin or expandin operation; Fig. 3 is a li e view after t e kerf has been cut in the upper mass of coal; Fig. 4 is a longitudinal section, showing the machine in operation of making the kerf in the upper mass of coal;

Specification of Letters Patent.

Fig. 5 is a diagrammatical plan view of the undercutting apparatus and the machine for removing the coal; and Fig. 6 is a view of the machine in the act of removing the coal.

The machine for making the preliminary undercut and the kerf in the upper` section of the coal may be any suitable apparatus, such as that forming the subject matter of a separate application for Letters Patent of the United States iled by me on the 16th day of May, 1914, Serial No. 839,325. The parts of this machine have been only illustrated diagrammatically, and it will only be referred to generally.

The numeral 2 designates the frame, which is mounted on the traction-wheels 3, connected up by suitable gearing to the motor 4. The steering-wheel 5 is provided, which is operated by the hand-wheel 6.

The frame 2 is mounted so as to normally incline downwardly at its forward end, and in order to provide for the raising of the forward end I provide the racks 7, which are carried by the truck 8. Pinions 9 on` Patented June 4, 1918. Application med August 14, 1914. serial No. 856,350.

the frame 2 engage the racks 7 said pinions being mounted on the shafts 10. Theshaft 10 has the worm-wheel 11, which is engaged by the worm 12 on the shaft 13. The shaft 13 is connected up at its rear end to the motor 4, and power is transmitted from the motor for raising and lowering the frame 2. The shaft 13 also has the worm 15, which engages the worm-wheel 16 from which power is communicated to drive the traction-wheels 3.

The shaft 17 is connected up with the motor-shaft, and said shaft carries a bevelpinion 18 which meshes with the bevel gearwheel 19 on the shaft 20. The shaft 20 carries a sprocket-wheel 21, around which the chain 22 passes, the chain at its forward end passing around the sprocket-wheels 23. The chain 22 carries the flights 24, which move along the pan 25. The iiights 24 have the cutters 26, which project beyond the pan at its forward end. The flights 24 are further provided with the disrupting devices 27, which are in the form of shoes, said disru tors forming the subject of a separate appl?- cation for Letters Patent of the United States filed by me on the 18th day of May, 1914, serial No. 839,335.

The motor 4 is provided with the connecting coupling 28 by means of which the cutter-bar 29 may be connected to said motor. The motor slides on the frame 2 so that it can be withdrawn therefrom so as to make the undercut when the bar 29 has been adjusted thereto. In Fig. 5 the motor is 1ndicated as having been withdrawn from the frame 2, and with the cutter-bar adjusted therein, is being used for making the undercut, the machine being pulled across the face of the coal by the ordinary cable 30 engag` ing pulleys and drums on the machine, and being connected up to the jacks or pillars 31. When the undercut has been made, the motor is then drawn back onto the frame 2. The undercut is indicated by the numeral 32. Shot-holes 33 are then drilled in the coal at points above the undercut at a suitable distance therefrom, and any suitable drilling apparatus being employed for making these shot-holes, said shot-holes being preferably drilled upwardly at an incline.

The explosive is introduced into the shotholes, and the coal shot or expanded, the force of the explosive being sufficient to lower the coal below the shot-holes down into the undercut without breaking the coal up into tine lumps, and merely separating the greater' portion of it along its lines of cleavage, although a small portion may drop down in front in the form of loose lumps. The larger portion of the coal between the shot-holes and the floor of the mine will be separated more or less along the lines of cleavage, and the adhesions between the lumps almost entirely released, although the individual lumps of coal will retain their individual relations or positions in the original bed of coal. The coal above the shot-holes will be released partially of the adhesions between the lumps, but the body of the coal will not be ordinarily moved from its original position, but will be released or cracked along its lines of cleavage.

The machine is then brought up into position as indicated in Fig. 4:, and the cutterbar 29 is introduced into the space 34 formed by the lowering of the coal into the undercut. The cutter-bar 29 is then moved upwardly by moving up the front end of the frame of the machine, and a kerf 35 is cut in the upper section of coal as indicated in Fig. 3. The machine is then withdrawn and the cutter-bar removed. This cutting of the kerf 35 releases the coal on three sides, namely, below at the front face, and on the side sheared, so that the force of gravitation may act effectually on the mass and the adhesions between the lumps or the attraction on the lines of cleavage between the lumps is Jfurther weakened so that the coal can be dislodged from below by the machine, which is brought up into the position indicated in Fig. 6. The advancing machine cuts in under the mass of coal, and the flight-cutters cutting their way under and loosening the coal and break it into lumps, while the disruptors 27 by their passage under the coal, give an undulating effect, which tends to release the coal in large lumps, which drop on the pan 25, and are carried by the conveyer back to the rear of the machine to be discharged into a conveyer 38 to be discharged therefrom into a pitwagon.

As the front of the machine advances, it also simultaneously rises as indicated in dotted lines, Fig. 6, and the coal above the shot-holes is dislodged by the action of the machine, and the coal which has been weakened by the kerf 35 drops in lumps upon the pan and is conveyed along the same by the ights.

What l claim is:

1. The method of mining coal consisting in under-cutting the mass of coal, expanding by explosive action the coal at a point above the undercut, thereby moving the coal below said point of expansion into the undercut and at the same time separating the coal above the point of expansion along its lines of cleavage by the expansion action, making a kerf in the upper mass of coal at an angle to the lines of the original undercut, and removing the coal.

2. The method of mining coal consisting in making an undercut in the mass of coal, expanding by explosive action the coal at a point above the undercut, thereby lowering the coal below said point of expansion into the undercut, expanding the coal lowered into the undercut along its lines of cleavage as well as the coal above the point of expansion, making a kerf in the upper mass of coal at an angle to the line of the ori nal undercut, and undermining the coal a ong the line of the undercut, dislodging and conveying the same away.

3. The method of mining coal consistin in making an undercut in the wall of coa expanding by explosive action the coal at a point above the undercut, thereby lowering the coal below the point of expansion into the undercut, expanding the coal so lowered along its lines of cleavage as well as the coal above the point of expansion, making a kerf in the upper mass of coal at an angle to the line of the original undercut, and applying an upward force in the mass of coal, dislodging and conveying the coal away.

4. The method of mining coal consisting in making a cut in the solid coal, expanding the coal by explosive action thereby releasing it along its lines of cleavage, making a shearing cut in the loosened mass of the coal at an angle to the original cut, and subsequently introducing conveying and dislodging forces beneath the mass of coal whereby the coal is dislodged and conveyed away.

5. The method of mining coal consistin neath the mass of coal whereby the coal is in making a horizontal eut in the solid coa dislodged and conveyed away. and introducing expanding explosive forces In testimony whereof Lfthe said HARRY A. Within the solld of the coal, whereby the KUHN, have hereunto set m hand.

5 coal is loosened from the solid along its Y H ARR A. KUHN.

lines of cleavage, making a vertical cnt Witnesses: along the mass of loosened coal, and intro ROBT. D. TOT'I'EN,

duoing dislodging and conveying forces be- JOHN F. Wm..

Copies o! this patent may be obtained to! avc cents each, by addressing the "communicant o! hun,

" Wuhinitn, D.0." 

